Diving with nitrox then flying

[Painter]

I recently did four dives over two days to approximately 70 feet using a 35% nitrox mix. I was
already on the plane when I realized that the advised 24 hours had not elapsed since my last dive...it had only been 18 hours. I was a little nervous, but didn't feel anything and that was two weeks ago.
Was it the nitrox, was 18 hours enough, a combination of both, or was I just lucky?

I did meet a guy once who said I was crazy to worry about flying within 24 hours after diving. that he did it all the time. Personally, I'd rather not take the chance.

 

[boulderjohn]

I recently did four dives over two days to approximately 70 feet using a 35% nitrox mix. I was
already on the plane when I realized that the advised 24 hours had not elapsed since my last dive...it had only been 18 hours. I was a little nervous, but didn't feel anything and that was two weeks ago.
Was it the nitrox, was 18 hours enough, a combination of both, or was I just lucky?

I did meet a guy once who said I was crazy to worry about flying within 24 hours after diving. that he did it all the time. Personally, I'd rather not take the chance.

Who advised 24 hours?

The DAN Americas' recommendation for those dives is 18 hours. That is what is taught in PADI courses. They advise 12 hours for single dive exposure and 18 for multiple dives.

 

[Boarderguy]

The Navy will fly a diver within 2 hours if needed... anything over 12 and you'll be fine

 

[boulderjohn]

The Navy will fly a diver within 2 hours if needed... anything over 12 and you'll be fine

The Navy has ascent to altitude tables that break down recommended times to the number of hours needed after dives, depending upon the diver's pressure group after the last dive.

 

[broncobowsher]

Nitrox isn't anything special when it comes to flying.

 

[boulderjohn]

Nitrox isn't anything special when it comes to flying.

Actually, it would be if you were using the US Navy's ascent to altitude table to determine fly time, since it would affect your final pressure group, but, let's face it, not many people would know what to do with that.

 

[Joneill]

I recently did four dives over two days to approximately 70 feet using a 35% nitrox mix. I was
already on the plane when I realized that the advised 24 hours had not elapsed since my last dive...it had only been 18 hours. I was a little nervous, but didn't feel anything and that was two weeks ago.
Was it the nitrox, was 18 hours enough, a combination of both, or was I just lucky?

I did meet a guy once who said I was crazy to worry about flying within 24 hours after diving. that he did it all the time. Personally, I'd rather not take the chance.

You were fine:
Flying After Diving - Divers Alert Network

 

[Dan G]

The Navy will fly a diver within 2 hours if needed... anything over 12 and you'll be fine

This is not sound advice. To reiterate John's post, this is from the DAN website:

"...the flying-after-diving guidelines for recreational diving call for a minimum 12-hour surface interval (SI) after single no-decompression dives, an 18-hour SI after multiple dives per day or multiple consecutive days of diving, and a “substantially longer” than 18-hour SI after decompression dives (Sheffield and Vann 2004). The “substantially longer” text was used to acknowledge the fact that we did not have sufficient data for precise recommendations, but it is a common rule of thumb that a 24-hour SI is desirable for decompression dives."

 

[BoltSnap]

Different point of view from DAN Europe:

Flying After Diving: Finally, the Facts (Not Just Theory)

 

[boulderjohn]

Different point of view from DAN Europe:

Flying After Diving: Finally, the Facts (Not Just Theory)

That test was simply infuriating.

They tested people for bubbles following a 24 hour surface interval, and they found that all but a minority of "bubble-prone" divers were clear. Here is what they concluded, with my emphasis added:

The examination of divers in the airport before the return trip, in which no bubbles were observed, has allowed us to estimate that an interval of 24 hours wait time is sufficient when remaining at sea level, so no bubbles can form.​

​

In other words, they waited until 24 hours to do the test and determined that 24 hours was sufficient, but not that it was necessary. Why they did not test them at the customary 18 hours is a mystery. They might have been clear then, too. To put it another way, they could have tested them at a full week after diving and determined that a full week of surface interval is sufficient to allow the diver to fly, but that does not mean a full week is necessary.